Gasket Design Guide & Considerations

Since it is usually not economical to obtain fluid-tight joints by machining, a gasket is commonly inserted between the contact faces of a joint. Tightening the fastening bolts causes the gasket material to flow into minor imperfections resulting in a fluid-tight seal.

The following information is intended only as a general overview of the design considerations involved in the proper application of a gasket-type seal. AMG Products will be pleased to put its decades of design and production experience to work solving your specific sealing problems.

General Recommendations

The accompanying chart illustrates some of the common applications of metallic and semi-metallic gaskets.

Electro / Chemical Corrosion

Gasket material must be compatible with the surfaces it contacts. The tendency for a metal to enter into solution (corrode) is a function of its electrode potential which is an inherent property of each element.

If dissimilar metals are externally connected, galvanic action occurs in which the metal with the higher electrode potential exerts a voltage which causes the lower (less noble) metal to corrode. The farther apart the metals are in the table, the greater the potential difference with a resulting greater rate of corrosion.

Bolting Specifications

A gasket’s mechanical environment must be known. Are the flanges flat, raised, grooved, etc.? Flange and bolt size is determined by the size of piping and the operating pressure. Bolts should be located central to the flange width. The bolt spacing for low pressure service should not exceed seven (7) times the bolt diameter. The bolt spacing for high pressure service should not exceed 3½ times the bolt diameter. Weak flanges and high internal pressure may both reduce the maximum workable bolt spacing.

Flange Clamping Pressure

The flange clamping pressure is derived from the clamping bolts and directly relates to the tightening torque. Numerous variables in bolting efficiencies prevent charting from being exact. The following chart assumes the bolts are not dry, rough, or rusted and that high friction items are not used. Also, that the flanges and bolt spacings are such that the pressure is constant over the entire gasket area. The chart gives a range of estimated pressure. The compression pressure will normally fall in this range near the lower figure. The high figure should be considered as the possible load applied to the bolt at this rate of torque. The compression in pounds per bolt is multiplied by the number of bolts to determine the total gasket load in pounds.

Why Chose AMG?

AMG is a metallic gasket and shim manufacturer centrally located in the heart of Ohio. Besides our over 100 years of experience in the metals movement industry, what sets us apart from our competition is our cost effective stamping process and vast array of secondary capabilities which makes AMG Products a “one stop shop”.

AMG Industries is a Lean Manufacturing facility practicing SMED and Just in Time delivery. AMG Industries’ capabilities include Progressive dies, Hovis dies, Compound dies, Deep Draw dies, Flange, and Trim dies.

AMG Industries produces a wide range of metal gaskets and shims for customers in the transportation, pump, motor, heavy equipment, and compressor industries.

By keeping as much as possible under “one roof”, we control what’s most important to you; quality, cost and on time delivery.

Whatever your requirements may be, AMG is there to provide you with the solution your customer expects from you.